Abstract: A secure optical data disc comprising an electronic article surveillance tag embedded within a layered disc structure comprising first and second substrates is disclosed. The tag is placed within a non-readable zone (i.e., one that does not have data tracks) of the secure disc. Layer-wise, the tag is either sandwiched between the two substrates or alternatively embedded within one of the two substrates. In the case where the tag is sandwiched between first and second substrates, a bonding layer occupies a space radially outward from the tag. The bonding layer holds the first and second substrates together thereby forming the secure disc.

Abstract: A secure optical data disc comprising an electronic article surveillance tag embedded within a layered disc structure comprising first and second substrates is disclosed. The tag is placed within a non-readable zone (i.e., one that does not have data tracks) of the secure disc. To improve signal quality of the tag, the reflective metal layer thickness is minimized and discontinuities are introduced on the reflective metal layer. A first discontinuity separates a data track region of the disc from a mirror/ID band region. A second, radial discontinuity opens the mirror/ID band ring.

Abstract: A secure optical data disc comprising an electronic article surveillance tag embedded within a layered disc structure comprising first and second substrates is disclosed. The tag is placed within a non-readable zone (i.e., one that does not have data tracks) of the secure disc. Layer-wise, the tag is either sandwiched between the two substrates or alternatively embedded within one of the two substrates. In the case where the tag is sandwiched between first and second substrates, a bonding layer occupies a space radially outward from the tag.. The bonding layer holds the first and second substrates together thereby forming the secure disc.

Abstract: A high density disc having a data area which is set such that compatibility is secured in the same drive while maintaining a superior recording/reproducing feature, is disclosed. The high density disc has a center hole, a clamping area, a data area where user data is recorded, a lead in area located at the inner side of the data area, and a lead out area located at the outer side of the data area. In the high density disc in which the diameter of the center hole is 10 mm or more, the inner diameter of the clamping area is characteristically within a range of 20–26 mm. Also, the inner diameter of the data area is characteristically within a range of 35–40 mm. Therefore, while a conventional disc drive is still used, the size of the high density disc decreases and a recording capacity can be increased.

Abstract: A recording medium apparatus includes a base plate formed with a stop portion, a holder being slidable on the base plate while holding a recording medium inserted in the holder, and a reversing spring, of which pressing direction changes in accordance with a position of the holder, a first end of the reversing spring being locked on the base plate and a second end of the reversing spring being locked on the holder. The reversing spring has an arc portion between the first and the second ends, the circular portion extends in a plane surface. The stop portion is locked in the holder so as to fix the holder in a predetermined position.